Allergic rhinitis and conjunctivitis caused by tree pollen can severely impact children’s quality of life during the spring season. While a sublingual immunotherapy (SLIT) tablet for tree pollen allergies has already shown efficacy and safety in adults and adolescents, the TT-06 phase III trial (EudraCT 2020-004372-17) is the first to assess its use in children aged 5–17.1
The abstract “SQ tree SLIT-tablet is well tolerated in children with tree pollen allergic rhinitis and/or conjunctivitis in the TT-06 phase III trial” was presented at EAACI 2025, Glasgow, 13–16 June 2025. In this Q&A, Dr Rémi Gagnon (Clinique Spécialisée en Allergie de la Capitale, Québec, Canada) highlights the burden of tree pollen-induced allergic rhinitis and/or conjunctivitis (AR/C) in children and discusses the methodology and findings from the TT-06 phase III trial.
Q. How does allergic rhinitis and/or conjunctivitis (AR/C) induced by tree pollen impact the quality-of-life of patients?
Allergic rhinitis can cause persistent symptoms of a runny, itchy nose and itchy, swollen eyes. This can significantly impact the quality of life of patients, disrupting sleep and causing fatigue, impairing sport/daily activities and other outdoor activities, and causing lower school and work productivity. Allergic rhinitis induced by tree pollen can be caused by a range of trees, for example alder, hazel, birch and oak; meaning that patients can suffer from allergic rhinitis symptoms for several months during the spring. Furthermore, patients can also suffer from other comorbidities, such as oral food syndrome and asthma.
Q. What clinical data already supported the SQ tree SLIT-tablet prior to the phase III trial?
A previous phase III of the SQ tree SLIT-tablet has been conducted in a population of adults and adolescents (above 12 years of age) confirming clinical efficacy and safety in this population. The TT-06 trial is the first phase III investigating the efficacy and safety of the SQ tree SLÍT-tablet in a paediatric population (5–17 years of age).
Q. Could you give a brief overview of the phase III trial design and methodology?
The TT-06 trial was a double-blind, placebo-controlled phase III trial that randomised 952 children (5–17 years of age) 1:1 to receive either SQ tree SLIT-tablet or placebo. Children were treated for ≥12 weeks prior to the expected start of the tree pollen season, and continued treatment until the end of the first pollen season. Both treatment groups had free access to symptom-relieving medications throughout the trial. During the pollen season, the subjects reported daily symptoms (4 nasal symptoms and 2 ocular symptoms) and use of symptom-relieving medication (antihistamines and/or nasal corticosteroids) in an electronic diary. These patient-reported data were used to assess the clinical efficacy. The primary endpoint in the trial was the total combined score (based on clinical symptoms and medication use) during the birch pollen season.
Q. What were the findings from the study and what was the clinical relevance of these findings?
The TT-06 trial demonstrated clinical efficacy and safety of the SQ tree SLIT-tablet in children 5–17 years of age. There was a statistically significant difference in primary endpoint in those treated with the SQ tree SLIT-tablet versus patients treated with placebo. These findings support the SQ tree SLIT-tablet as a clinically relevant treatment option in children insufficiently controlled on symptom-relieving medications. The additional safety findings support that the SQ SLIT-tablet is well-tolerated in children. The most common treatment-related adverse events were local allergic reactions, such as oral pruritus, throat irritation and tongue pruritus.
References
- Clinicaltrialsregister.eu. Efficacy and safety of the SQ tree sublingual immunotherapy tablet in children and adolescents (5 through 17 years of age) with moderate to severe allergic rhinitis and/or conjunctivitis induced by pollen from birch and trees belonging to the birch homologous group. Available at: https://www.clinicaltrialsregister.eu/ctr-search/search?query=2020-004372-17 (accessed 18 June 2025).
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This content has been developed independently by Touch Medical Media for touchRESPIRATORY. It is not affiliated with the European Academy of Allergy and Clinical Immunology (EAACI). Views expressed are the speaker’s own and do not necessarily reflect the views of Touch Medical Media.
Editor: Victoria Smith, Senior Content Editor.
Cite: Rémi Gagnon. TT-06 Trial: SQ Tree SLIT-Tablet Demonstrates Clinical Benefit in Paediatric Tree Pollen Allergy. touchRESPIRATORY. 30 June 2025.
Disclosures: This short article was prepared by touchRESPIRATORY in collaboration with Rémi Gagnon. touchRESPIRATORY utilize AI as an editorial tool (ChatGPT (GPT-4o) [Large language model]. https://chat.openai.com/chat.) The content was developed and edited by human editors. No fees or funding were associated with its publication.
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